diff --git a/pkg/compact/compact.go b/pkg/compact/compact.go
index 6465f16927e..a469080b38c 100644
--- a/pkg/compact/compact.go
+++ b/pkg/compact/compact.go
@@ -997,51 +997,62 @@ func (cg *Group) compact(ctx context.Context, dir string, planner Planner, comp
 	begin := time.Now()
 
 	toCompactDirs := make([]string, 0, len(toCompact))
-	for _, meta := range toCompact {
-		bdir := filepath.Join(dir, meta.ULID.String())
-		for _, s := range meta.Compaction.Sources {
+	g, ctx := errgroup.WithContext(ctx)
+	for _, m := range toCompact {
+		bdir := filepath.Join(dir, m.ULID.String())
+		for _, s := range m.Compaction.Sources {
 			if _, ok := uniqueSources[s]; ok {
 				return false, ulid.ULID{}, halt(errors.Errorf("overlapping sources detected for plan %v", toCompact))
 			}
 			uniqueSources[s] = struct{}{}
 		}
 
-		tracing.DoInSpanWithErr(ctx, "compaction_block_download", func(ctx context.Context) error {
-			err = block.Download(ctx, cg.logger, cg.bkt, meta.ULID, bdir)
-			return err
-		}, opentracing.Tags{"block.id": meta.ULID})
-		if err != nil {
-			return false, ulid.ULID{}, retry(errors.Wrapf(err, "download block %s", meta.ULID))
-		}
+		func(meta *metadata.Meta) {
+			g.Go(func() error {
+				tracing.DoInSpanWithErr(ctx, "compaction_block_download", func(ctx context.Context) error {
+					err = block.Download(ctx, cg.logger, cg.bkt, meta.ULID, bdir)
+					return err
+				}, opentracing.Tags{"block.id": meta.ULID})
+				if err != nil {
+					return retry(errors.Wrapf(err, "download block %s", meta.ULID))
+				}
 
-		// Ensure all input blocks are valid.
-		var stats block.HealthStats
-		tracing.DoInSpanWithErr(ctx, "compaction_block_health_stats", func(ctx context.Context) error {
-			stats, err = block.GatherIndexHealthStats(cg.logger, filepath.Join(bdir, block.IndexFilename), meta.MinTime, meta.MaxTime)
-			return err
-		}, opentracing.Tags{"block.id": meta.ULID})
-		if err != nil {
-			return false, ulid.ULID{}, errors.Wrapf(err, "gather index issues for block %s", bdir)
-		}
+				// Ensure all input blocks are valid.
+				var stats block.HealthStats
+				tracing.DoInSpanWithErr(ctx, "compaction_block_health_stats", func(ctx context.Context) error {
+					stats, err = block.GatherIndexHealthStats(cg.logger, filepath.Join(bdir, block.IndexFilename), meta.MinTime, meta.MaxTime)
+					return err
+				}, opentracing.Tags{"block.id": meta.ULID})
+				if err != nil {
+					return errors.Wrapf(err, "gather index issues for block %s", bdir)
+				}
 
-		if err := stats.CriticalErr(); err != nil {
-			return false, ulid.ULID{}, halt(errors.Wrapf(err, "block with not healthy index found %s; Compaction level %v; Labels: %v", bdir, meta.Compaction.Level, meta.Thanos.Labels))
-		}
+				if err := stats.CriticalErr(); err != nil {
+					return halt(errors.Wrapf(err, "block with not healthy index found %s; Compaction level %v; Labels: %v", bdir, meta.Compaction.Level, meta.Thanos.Labels))
+				}
 
-		if err := stats.OutOfOrderChunksErr(); err != nil {
-			return false, ulid.ULID{}, outOfOrderChunkError(errors.Wrapf(err, "blocks with out-of-order chunks are dropped from compaction:  %s", bdir), meta.ULID)
-		}
+				if err := stats.OutOfOrderChunksErr(); err != nil {
+					return outOfOrderChunkError(errors.Wrapf(err, "blocks with out-of-order chunks are dropped from compaction:  %s", bdir), meta.ULID)
+				}
 
-		if err := stats.Issue347OutsideChunksErr(); err != nil {
-			return false, ulid.ULID{}, issue347Error(errors.Wrapf(err, "invalid, but reparable block %s", bdir), meta.ULID)
-		}
+				if err := stats.Issue347OutsideChunksErr(); err != nil {
+					return issue347Error(errors.Wrapf(err, "invalid, but reparable block %s", bdir), meta.ULID)
+				}
 
-		if err := stats.PrometheusIssue5372Err(); !cg.acceptMalformedIndex && err != nil {
-			return false, ulid.ULID{}, errors.Wrapf(err,
-				"block id %s, try running with --debug.accept-malformed-index", meta.ULID)
-		}
+				if err := stats.PrometheusIssue5372Err(); !cg.acceptMalformedIndex && err != nil {
+					return errors.Wrapf(err, "block id %s, try running with --debug.accept-malformed-index", meta.ULID)
+				}
+
+				return nil
+			})
+		}(m)
 		toCompactDirs = append(toCompactDirs, bdir)
 	}
+
+	if err := g.Wait(); err != nil {
+		return false, ulid.ULID{}, err
+	}
+
 	level.Info(cg.logger).Log("msg", "downloaded and verified blocks; compacting blocks", "plan", fmt.Sprintf("%v", toCompactDirs), "duration", time.Since(begin), "duration_ms", time.Since(begin).Milliseconds())
 
 	begin = time.Now()
diff --git a/pkg/objstore/objstore.go b/pkg/objstore/objstore.go
index c2f3c126438..40f71b324e4 100644
--- a/pkg/objstore/objstore.go
+++ b/pkg/objstore/objstore.go
@@ -19,6 +19,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
+	"golang.org/x/sync/errgroup"
 
 	"github.com/thanos-io/thanos/pkg/runutil"
 )
@@ -259,29 +260,36 @@ func DownloadDir(ctx context.Context, logger log.Logger, bkt BucketReader, origi
 		return errors.Wrap(err, "create dir")
 	}
 
+	g, ctx := errgroup.WithContext(ctx)
+
 	var downloadedFiles []string
-	if err := bkt.Iter(ctx, src, func(name string) error {
-		dst := filepath.Join(dst, filepath.Base(name))
-		if strings.HasSuffix(name, DirDelim) {
-			if err := DownloadDir(ctx, logger, bkt, originalSrc, name, dst, ignoredPaths...); err != nil {
-				return err
-			}
-			downloadedFiles = append(downloadedFiles, dst)
-			return nil
-		}
-		for _, ignoredPath := range ignoredPaths {
-			if ignoredPath == strings.TrimPrefix(name, string(originalSrc)+DirDelim) {
-				level.Debug(logger).Log("msg", "not downloading again because a provided path matches this one", "file", name)
+	err := bkt.Iter(ctx, src, func(name string) error {
+		g.Go(func() error {
+			dst := filepath.Join(dst, filepath.Base(name))
+			if strings.HasSuffix(name, DirDelim) {
+				if err := DownloadDir(ctx, logger, bkt, originalSrc, name, dst, ignoredPaths...); err != nil {
+					return err
+				}
+				downloadedFiles = append(downloadedFiles, dst)
 				return nil
 			}
-		}
-		if err := DownloadFile(ctx, logger, bkt, name, dst); err != nil {
-			return err
-		}
-
+			for _, ignoredPath := range ignoredPaths {
+				if ignoredPath == strings.TrimPrefix(name, string(originalSrc)+DirDelim) {
+					level.Debug(logger).Log("msg", "not downloading again because a provided path matches this one", "file", name)
+					return nil
+				}
+			}
+			return DownloadFile(ctx, logger, bkt, name, dst)
+		})
 		downloadedFiles = append(downloadedFiles, dst)
 		return nil
-	}); err != nil {
+	})
+
+	if err == nil {
+		err = g.Wait()
+	}
+
+	if err != nil {
 		downloadedFiles = append(downloadedFiles, dst) // Last, clean up the root dst directory.
 		// Best-effort cleanup if the download failed.
 		for _, f := range downloadedFiles {